Precommercial thinning in a northern conifer stand: 18-year results

Four levels of precommercial thinning were applied with and without fertili zation in a young, even-aged stand of northern conifers in east-central Mai ne. After 18 years, precommercial thinning resulted in longer and wider cro wns and greater survival, growth, and yield of selected crop trees compared to untreated controls. Growth and yield were greater with uniform spacing at approximately 2.4 x 2.4 m and 1.5-m row thinning with crop-tree release in residual strips than with row thinning without crop-tree release. Contro l of stand species composition was greatest with uniform spacing. Fertiliza tion had no significant effect.